Mhh.. I don't know if this will help you, as my code is generated code from
the WSDL and I don't know where it could fit in your code, but here I go:

[System.Web.Services.WebServiceBindingAttribute(Name="SomeNameSoapBinding",
Namespace="SomeNS")]
public class KMURatingWsService :
System.Web.Services.Protocols.SoapHttpClientProtocol {
...
   [System.Web.Services.Protocols.SoapRpcMethodAttribute("SomeMethod",
RequestNamespace="SomeNS",   ResponseNamespace="SomeNS")]
   [return:
System.Xml.Serialization.SoapElementAttribute("SomeMethodReturn")]
   public ResultType SomeMethod(ParamType1 param1, ParamType2 param2) {
   ...
   }
   ... classes for ParamType1, ParamType2 and ResultType like
   [System.Xml.Serialization.SoapTypeAttribute("Param1Type", "SomeURL")]
   public class Param1Type {
       ... just a sequence of int's and string's
   }
}
Again, I doubt that this will help you very much, as the WSDL defines the
binding protcoll needed for accessing the WS. So the binding is something
that is defined in the WSDL. If you don't have a WSDL what would the binding
be good for?

Wouldn't it be better for you to construct your own XML, so that it matches
the XML SOAP envelope required by "their" web service and post the request
"by hand" using HttpWebRequest/HttpWebResponse. See
http://msdn.microsoft.com/msdnmag/issues/01/09/cweb/ as a first start.